248 PovaAH: A CRITICAL STUDY OF 
basis for separation of species. In the first place, for example, he 
separates Mucor Jansseni from the remaining species by the 
fact that it grows poorly on “wort gelatin’’ but well on bread; 
in the second place, he separates Mucor Rouxii from the last four 
species by the fact that on either bread or ‘‘wort gelatin’”’ it forms 
a short yellow down, while the remaining species form a turf 1-3 
cm. tall. 
Sumstine (1910), in his thirty page publication on the North 
American Mucorales, throws to the winds all the work of the late 
contributors to the group (Fischer, Hagem, Lendner, etc.). 
He separates from Mucor (Mich.) L., as ordinarily understood, the 
genera Hydrophora Tode (which had long been discarded for the 
name Mucor) and Calyptromyces Karst. (a genus founded merely 
on the fact that the sporangiophores are branched). In speaking 
of this last genus, Sumstine says: “‘ This complex group contains 
some forty described species but the relationship of these species 
is not well known. There seem to be two modes of branching, 
monopodial and sympodial. This branching has been made the 
basis for the division into two groups, Racemo-Mucor and Cymo- 
Mucor. . . . This division, however, is uncertain and unsatis- 
factory.’’ It is, in the writer’s opinion, as unreasonable to main- 
tain two genera, one for branching and the other for simple forms, 
as to separate species according to their mode of branching; 
for it has been found, during the course of this study, that the 
former distinction is practically as difficult as the one to which 
Sumstine objects. To give an idea of the confusion caused by 
the arrangement which this author proposes, let us consider a 
few cases. His Mucor Mucedo L. is the common Rhizopus nigri- 
cans Ehrenb., Hydrophora stercorea Tode is Mucor Mucedo 
Fresen., Hydrogera obliqua (Scop.) O. Kuntze is Pilobolus crystal- 
linus (Web. & Wigg.) Tode, and Calyptromyces ramosus Karst. 
is Mucor racemosus Fresen. It is the writer’s opinion that the 
only new things in this paper are names for plants which we fail 
to recognize under their new guise. 
